package section8;
interface FaceA{
    static final double PI=3.14;
    abstract double area();
}
interface FaceB{
    abstract void volume();
}
class CyLinder8_13 implements FaceA,FaceB{
    private double radius;
    private int height;
    public CyLinder8_13(double r,int h){
        radius=r;
        height=h;
    }

    @Override
    public double area() {
        return PI*radius*radius;
    }

    @Override
    public void volume() {
        System.out.println("圆柱体的体积="+area()*height);
    }
}
public class App8_13 {
    public static void main(String[] args) {
        CyLinder8_13 volu=new CyLinder8_13(13.5,6);
        volu.volume();
    }
}
